Yah so the few helm charts I have used, I had not seen a huge value. If I wanted to change something without a hook, I end up using my own dockerfile anyway.. so I guess it is helpful as just a reference on how to get a service to work, but not that useful for prod deploys.
We've standardized on helm for prod deploys. Perhaps it's not a huge value, but it is a convenient way to bundle together a set of configs, templatize them and manage them.
For example, if you want to deploy a distributed TensorFlow training on kubernetes with multiple parameter servers and task servers, it is a nightmare to do just with kubernetes yaml templates. Helm and it's go templating makes it much much easier.